Method for beneficiating ores



United States Patent Office 3,149,788 Patented Sept. 22, 1964 a corporation of Nevada No Drawing. Filed Jan. 30, 1962, Ser. No. 169,963

7 Claims. (Cl. 241-20) The present invention relates as indicated to the benefication of ores and has more particular reference to the use of auxiliary flotation reagents for the froth flotation of various types of ores.

It has long been the desire of ore refiners to economically separate desirable minerals from ores by froth flotation, and to obtain the desired mineral values containing particles as large as 8 mesh and of a purity which meets the specifications of the industry. Effective froth flotation techniques and reagents for recovering the desired mineral values from their respective ores where the particles are minus 16 mesh are known; however, these prior art techniques and reagents are ineffective in the recovery of plus 14 mesh particles. The ores, therefore, have had to be ground to a minus 14 mesh size, and the refiners have had to resort to the use of additional costly operations and equipment in order to obtain plus 14 mesh particles of the desired minerals.

It is, therefore, the principal object of this invention to provide an economical method for the froth flotation of ores, which will result in a final product having a particle size on the order of from at least 8 mesh and of a desired purity.

Other objects of the present invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

Broadly stated, the present invention comprises the method of obtaining desired mineral values from ores by froth flotation, which comprises grinding said ore, pulping the ground ore, conditioning the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent and at least one auxiliary reagent selected from the group consisting of indane and alkyl substituted indanes said alkyl substituents having from 1 to 8 carbon atoms, subjecting said conditioned ore pulp to a froth flotation cell, and recovering said mineral values from said flotation cell.

From the foregoing broadly stated paragraph it will be seen that the present invention uses a combination of flotation reagents to condition the pulped ore so as to obtain the desired mineral values. The present admixture comprises as one component, long chain aliphatic amine collector reagents which are Well known to those skilled in the flotation art. These collector reagents selectively coat the particles to be floated, but only impart sufficient hydrophobic characteristics to effectively bring about the flotation of minus 14 mesh particles. However, by the addition of the alkylindanes and/or indane auxiliary reagents it is now possible to float by froth flotation substantially all of the desired material containing particles as large as 8 mesh.

It is my theory that the amine collector reagents selectively coat the materials to be floated and attract the auxiliary reagents which in turn impart a much greater hydrophobic characteristic and bring about the flotation of particles as large as 6 or 8 mesh. However, regardless of whether my theory is correct or not, the fact remains that by combining any of the well-known amine collector reagents with the above-defined indane and/ or alkylindanes, it is now possible to efficiently and economically float particles, by froth flotation, as large as 8 mesh.

As stated above, the amine collector reagents used in the present invention are the same as those used by ore refiners in prior flotation processes. These collector reagents are long chain aliphatic amines consisting of from 7 to 18 or more carbon atoms and are most commonly prepared from beef tallow. They are usually prepared as the salts of the amines, the most commonly used salt being the acetate, and they are purchased commercially as mixed aliphatic amine acetates.

The auxiliary reagents applicable to the present invention are indane and the alkylindanes, the alkyl portion of which contains from 1 to 8 carbon atoms. The following list is illustrative of these compounds:

3-ethylindane 3 -isopropylindane Z-n-butylindane 2-isoamylindane 3-n-hexylindane 3-isooctylindane It is to be clearly understood that the foregoing list is only a partial enumeration of the auxiliary reagents applicable to the present invention and is not intended to limit the invention.

Many of the present auxiliary reagents are naturally occurring compounds which can be obtained in a substantially pure state by the extraction and distillation of coal tar and petroleum oil fractions; additionally, any of the present auxiliary reagents can be readily synthesized in a substantially pure state.

There are also commercially available petroleum oil and coal tar fractions which are enriched in the present auxiliary reagents. These fractions contain from about 30 to 60 weight percent of mixed indane and alkylindanes, but are contaminated with other hydrocarbons such as naphthalene, naphthenes, alkyltetralins, paraflins and ale kylbenzenes. However, the hydrocarbon contaminants do not interefere with the functioning of the indane and alkylindanes, and such mixtures are applicable to the present invention and are less costly based on their indane and alkylindane than are the substantially pure compounds.

Thus, it will be noted that the indane and the alkylindanes can be used separately, or in combination, or in an admixture with other hydrocarbons. When the above petroleum and coal tar fractions are used, they must be present in such an amount as would provide the equivalent amount of the indane or the alkylindanes as would be required in the flotation process if they were to be used in a substantially pure state.

Froth flotation is used in two ways for thebeneficiation of ores. In one instance the desired mineral values are floated and recovered from the froth, such as in the 110- tation of:

(a) Potassium values from potassium bearing ores; (b) Spodumene from silica and mica feldspar; and (c) Mica and silica from cement rock.

While in the other instance the impurities are floated and discarded and the desired mineral values are recovered from the flotation cell, such as in the flotation of:

(a) Silica from. ilmenite;

(b) Silica from lepedolite;

(c) Calcite and silica from fluorspar;

(d) Silica from phosphate bearing ores; and (e) Silica from iron bearing ores.

In any froth flotation process where amine collector reagents are used, the addition of the defined auxiliary reagents permits the eflicient flotation of particles as large as 8 mesh. This brings about substantial savings in the cost of grinding, screening and flotation equipment and results in high yields of products having a higher than required purity.

So that the present invention is more clearly understood, the following examples are given for illustrative purposes:

Sylvinite ore was ground to a 8 mesh size and was slurried in a saturated brine composed of the soluble constituents of the ore. The slurry was then deslimed through a 100 mesh screen to remove the fines and insoluble matter, and a representative sample of the resultant ore pulp was found to contain 28 percent by weight of +14 mesh material. The ore pulp was then conditioned with an admixture of auxiliary reagent and amine collector reagent, and the conditioned ore pulp was added to a Fag flotation cell along with some clear saturated brine. The slurry was then aerated from the bottom of the cell and as froth formed at the surface it was removed carrying with it substantially all of the potash.

The following table shows results of tests performed following the above procedure. The rate of addition of reagents is measured in pounds of reagent per ton of crushed ore and the percent potassium chloride recovered is based on the percent potassium chloride in the ore pulp after desliming.

Table 1 Auxiliary Collector Percent Auxiliary Reagent Reagent, Reagent, K01

lbJton lh./ton Recovered of ore of ore lure Individual:

Intlnne a O. 40 0. 48 93. 96 2-methylindane O. 42 0. 50 95. 89 1,3-(limethylint1an0. 0. 45 0. 50 95. 04 3-etllylindnno 0. 45 0. 50 95. 28 3-isopropylindane. 0. 42 0.50 94. 86 l-n-hutylindane 0. 42 0. 48 96.13 3-isoumylin(lane 0. 45 0. 48 95. 22 3n octylindane 0. 45 0. 48 95. 56 M i :Ied:1

[K it l'l(- a V a lanethylindane I 42 0 50 31 Inrlaue a. Lil-dimethylindanc 0. 45 0. 50 96. 27 B-isopropylindano Itupure:

30W, lndaue and Alkylintlai'losv 50 A llrylhonzenes and Alkyltetralins 1. 40 0. 48 93. 53 20' Naphthalene and Allrylnaphthalenes 45% lntlane and Alkylin- (lanes 45 1, Alkylben zones and Alkyltotrallns 1. 0 0. 48 97. 53% Naphthalene and Naphthenes constituents of the ore.

Sylvinite ore was ground to a 8 mesh size and was slurried in a saturated brine composed of the soluble constituents of the ore. The slurry was then deslimed through a mesh screen to remove the fines and insoluble matter, and the deslimed ore was wet screened and divided into two fractions, one fraction containing the +16 mesh particles and the other fraction containing the -16 mesh particles. The +16 mesh fraction, comprising 40% by weight of the total material, was conditioned with an admixture of auxiliary reagent and amine collector reagent while the -16 mesh fraction was conditioned with only the amine collector reagent. After conditioning, the two fractions were added together to a Fag flotation cell along with some clear saturated brine. The slurry was then aerated from the bottom of the cell and as the froth formed at the surface it was removed carrying with it substantially all of the potash.

The following table shows results of tests performed following the above procedure. The rate of addition of reagents is measured in pounds per ton of crushed ore and the percent potassium chloride recovered is based on the percent potassium chloride in the ore pulp after deslirning.

Table II +16 Mesh Fraction 16 Mesh Fraction Percent Auxiliary Reagent K01 Re- Auxiliary Collector Collector covered Reagent Reagent Reagent lb./t0n lb./ton lb./ton of ore of ore of ore Pure Individual:

Indane 0.33 0.20 0.12 97.02 2-methyl1ndane... 0. 30 0. 20 0. 12 95. 73 1,3-d1methylindane 0. 30 0. 18 (1. 12 96.11 3-ethylindane i 0. 28 0.18 0.12 95. 81 3-1s0propyhndane 0. 32 0.18 0.12 96. 43 Q-n-butylindane 0.30 0. 18 0. 12 95.28 2-isoa1ny1indane 0. 30 0. 18 0. 12 95. 39 3-n-octylindane 0.30 0.18 0.12 95. 38 Mnriad:1

n ane 0. a2 0. 20 0.12 96.17 Indane 1,3-dimethylindane- 0. 32 0. 20 0.12 96. 09 3-isopropylindane 1m ure:

30% Indane and Alkylinso firir 0 y enzenes Alkyltetmuns 1.0 0. 20 0. 12 9G. 59 20% Naphthalene and Alkylnaphthalenes- 45% Indane and Alkylln- (lanes 45% Alkylbenzenes and Alkyltetralins 70 0. 20 0. 12 96. 18 5% Naphthalene and Naphthenes 5% Paralfms None 0 0.40 0.12 75.14

Sylvinite ore was ground to a minus 8 mesh size and was slurried in a saturated brine composed of the soluble The slurry was then deslimed through a 16 mesh screen to remove the insoluble matter and all material smaller than 16 mesh. The +16 mesh ore pulp was then conditioned with an admixture of auxiliary reagent and collector reagent, and the conditioned ore pulp was then added to a Fag flotation cell along with some clear saturated brine. The slurry was then aerated from the bottom of the cell and as the froth formed at the surface it was removed carrying with it substantially all of the potash.

The following table shows results of tests performed following the above procedure. The rate of addition of reagents is measured in pounds of reagent per ton of 8,

5 +16 mesh crushed ore and the percent potassium chloride recovered is based on the percent potassium chloride in the ore pulp after desliming.

Table III Collector Reagent, lb./ton of ore Auxiliary Reagent, lb./tn of ore Percent Auxlllar Rea ent K 1 y g Recovered Pure Individual:

Indane 2-methylindane a-ethylindane 3-isopropyllndane 0000. 0. 0 w (11 mooonoounuooooo O O QOOQOOOQ 5 0. 0. 00 OI O! UIOIUIUICYIOIUI o O ooooooc Mixed:

The concentrates recovered, as per the examples given, ranged in grade from about 95.2% to about 98.2% potassium chloride, which exceeds the minimum standard of purity set by the potash industry.

Although there are numerous variations which can be ,used in performing a froth flotation process, such as conditioning the ore pulp first with the amine collector reagent and then with the defined auxiliary reagents, in the preferred embodiment of the invention, 1 use the method as described above in Example II. I have found this method to be the most economically desirable process, as it requires a minimum of reagents with a minimum of equipment and handling.

It is important to note that the tables from the preceding examples indicate that the addition of auxiliary reagent and amine collector reagent provides an efficient flotation process where amine collector reagent alone does not. Although the examples shown are only for the benefication of sylvinite ore, the combination of auxiliary reagent and amine collector reagent works equally well in any of the prior art froth flotation processes which employed only amine collector reagent, and for the first time, provides the efficient recovery of particles as large as 8 mesh.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. The method of obtaining desired mineral values from ores by froth flotation which comprises grinding said ore, pulping the ground ore, conditioning the resultant ore pulp with a flotation reagent comprising an admixture of a long chainaliphatic amine collector reagent and at least one auxiliary reagent selected from the group consisting of indane and alkyl substituted indanes said alkyl substituents having from 1 to 8 carbon atoms, subjecting said conditioned ore pulp to a 6 froth flotation cell, and recovering said mineral values from said flotation cell.

.2. The method of obtaining desired mineral values from ores by froth flotation which comprises grinding said ore to a particle size of at least about 8 mesh, pulping the ground ore, conditioning the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent and at least one auxiliary reagent selected from the group consisting of indane and alkyl substituted indanes said alkyl sub: stituents having from 1 to 8 carbon atoms, subjecting said conditioned ore pulp to a froth flotation cell, and recovering said mineral values from said flotation cell.

3. The method of obtaining desired mineral values from ore by froth flotation which comprises grinding said ore to a particle size of at least about 8 mesh, pulping said ground ore, conditioning the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent and a combination of at least two auxiliary reagents selected from the group consisting of indane and alkyl substituted inclaims said alkyl substituents having from 1 to 8 carbon atoms, subjecting said conditioned ore pulp to a froth flotation cell, and recovering said mineral values from said flotation cell.

4. The method of obtaining desired mineral values from ores'by froth flotation which comprises grinding said ore to a particle size of at least about 8 mesh, pulping the ground ore, conditioning the resultant ore pulp with, a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent and a material selected from the group consisting of coal tar fractions and petroleum oil fractions, said fractions containing from about 30 to about 60 weight percent of a combination of materials selected from the group consisting of indane and alkyl substituted indanes said alkyl substituents having from 1 to 8 carbon atoms, subjecting said conditioned ore pulp to a froth flotation cell, and recovering said mineral values from said flotation cell.

5. The method of obtaining sylvite from sylvinite ore by broth flotation which comprises grinding said sylvinite ore to a particle size of at least about 8 mesh, pulping the ground ore, conditioning the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent and at least one auxiliary reagent selected from the group consisting of indane and alkyl substituted indanes said alkyl substituents having from 1 to 8 carbon atoms, subjecting said conditioned ore pulp to a froth flotation cell, and recovering substantially all of the sylvite from the resultant froth.

6. The method of obtaining sylvite from sylvinite ore by froth flotation which comprises grinding said sylvinite ore to a particle size of at least about 8 mesh, pulping said ground ore, conditioning the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine and a combination of at least two auxiliary reagents selected from the group consisting of indane and alkyl substituted indanes said alkyl substituents having from 1 to 8 carbon atoms, subjecting said conditioned ore pulp to a froth flotation cell, and recovering substantially all of the sylvite from the resultant froth.

7. The method of obtaining sylvite from sylvinite ore by froth flotation which comprises grinding said sylvinite ore to a particle size of at least about 8 mesh, pulping said ground ore, conditioning the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent and a material selected from the group consisting of coal tar 7 8 fractions and petroleum oil fractions, said fractions con- References Cited in the file of this patent taining from about 30 to about 60 Weight percent of :1 UNITED STATES PATENTS combination of materials Selected from th g p 0 329 493 Bacon 3 19 sisting of indane and alkyl substituted indanes said alkyl 1,9 4,33 Tschudy 13, 1934 substituents having from 1 to 8 carbon atoms, subjecting 5 2,672,236 Weinig Mar. 16, 1954 said conditioned ore pulp to a froth flotation cell, and OTHER REFERENCES gfiigfi i gi fi an of the Sylvlte from the re- Russian publication by Pylaev (Gornoye-Obag) (Date 1932, pages 22-30). 

1. THE METHOD OF OBTAINING DESIRED MINERAL VALUES FROM ORES BY FROTH FLOTATION WHICH COMPRISES GRINGIND SAID ORE, PULPING THE GROUND ORE, CONDITIONING THE RESULTANT ORE PULP WITH A FLOTATION REAGENT C OMPRISING AN ADMIXTURE OF A LONG CHAIN ALIPHATIC AMINE COLLECTOR REAGENT AND AT LEAST ONE AUXILLARY REAGENT SELECTED FROM THE GROUP CONSISTING OF INDANE AND ALKYL SUBSTITUTED INDANES SAID ALKYL SUBSTITUENTS HAVING FROM 1 TO 8 CARBON ATOMS, SUBJECTING SAID CONDITIONED ORE PULP TO A FORTH FLOTATION CELL, AND RECOVERING SAID MINERAL VALUES FROM SAID FLOTATION CELL. 